A San Francisco talk radio station pre-empted three hours of programming on Friday in response to a campaign by bloggers who have recorded extreme comments by several hosts and passed on digital copies to advertisers.

The lead blogger, who uses the name Spocko, said that he and other bloggers had contacted more than 30 advertisers on KSFO-AM to inform them of comments made on the air and to ask them to pull their ads.

The comments were also posted on Spocko’s Web site, spockosbrain.com. In response, ABC Radio Networks, which owns KSFO and which in turn is owned by the Walt Disney Company, sent letters to the site’s service provider, demanding the clips be taken down from its servers. The provider complied, raising the issue of what constitutes fair use of copyrighted material by a critic.

In an unusual cap to a simmering controversy, four talk radio hosts at KSFO-AM themselves played the clips on Friday, which had, in some cases, drawn national attention for language considered racially insensitive, religiously intolerant or containing violent imagery. The broadcast contained the occasional carefully measured apology for language that “could have been put more elegantly,” as one host, Melanie Morgan, described her comment — “We’ve got a bull’s eye painted on her big wide laughing eyes” — about Nancy Pelosi, the Democratic speaker of the House of Representatives, who is from San Francisco. “But Ms. Morgan added that her words were obviously a political metaphor that had to be distorted by critics to appear violent.

Ms. Morgan said that the on-air talent had “been reissued guidelines from the company about violent rhetoric and we’ve reviewed those rules and we don’t believe that we have crossed any single line.” But the hosts were uniformly defiant against the bloggers, who were called “crackpots with keyboards” and accused of using “guerrilla tactics.”

Spocko had recorded and disseminated other clips from the station in an effort to alarm advertisers. In one, Brian Sussman, an evening host on KSFO, described Senator Barack Obama, Democrat of Illinois, as a “halfrican,” because he has one African parent and one white parent. In another, from 2005, he challenged a caller who said he was not a Muslim to prove it by repeating back an insult to Allah. Mr. Sussman apologized for both comments during Friday’s three-hour show.

In an interview, Spocko, who described himself as being in his “late 40s and a communications professional,” said he was appalled by what he heard on KSFO. Among the advertisers Spocko contacted, and who have been reported in The San Francisco Chronicle to have stopped advertising at KSFO were Bank of America, MasterCard and the Michigan Economic Development Corporation. During the Friday show, one of the hosts, Lee Rodgers, read an e-mail message asking if the station had lost any sponsors so the listener could, in turn, boycott the former sponsors. Ms. Morgan said “one advertiser — exactly one” had left the station.

When reached at his office, KSFO-AM’s program director, Ken Berry, said he felt “the three-hour broadcast best spoke for us” and referred other questions to ABC. An ABC spokeswoman had no comment.

Spocko’s campaign became more widely followed when his blog was taken down by his Internet service provider, 1&1 Internet, of Chesterbrook, Pa., after ABC lawyers sent the company a cease and desist letter on Dec. 22.

1&1 says “the decision was made to remove the copyrighted material from our servers until the matter is resolved, whether by the parties involved or the judicial system.”

Spocko has since switched to a different Web hosting company. His lawyer, Matt Zimmerman of the Electronic Frontier Foundation, a nonprofit digital rights group based in San Francisco, says that 1&1 acted too quickly in response to the ABC letter, which he described as saber-rattling rather than a valid notice under the Digital Millennium Copyright Act, an updating of copyright laws from 1998.